General: Fire Safety Technology (4) Fire Inspection for Flammable and Explosive Sites

The first section   Building explosion-proof

Check content

1. Determination of explosion hazard area

2. Explosion-proof measures taken

It mainly checks whether there are explosion-proof plants and warehouses that have taken effective explosion-proof measures. The inspection requirements are:

( 1 ) Class A buildings that emit flammable gas and flammable vapors that are heavier than air, and Class B plants that have dust and fiber explosion hazards. The ground on which sparks are not emitted. When using insulating material as a whole surface layer, take anti-static measures. The trench should not be installed under the ground. When it is necessary to install it, the cover plate shall be tight and tightly packed with non-combustible materials. The trench shall be an effective measure to prevent the accumulation of flammable gas, flammable vapour and dust, and fibers in the trench, and be connected with the neighboring factory buildings. The use of non-flammable fireproof material seals.

( 2 ) The interior surface of the factory building emitting combustible dust and fiber is smooth, smooth and easy to clean.

( 3 ) Use and produce Class A, B, and C liquid plants. The pipes and trenches must not be connected to the pipes and trenches of adjacent plants. Sewage installations should be installed in the sewers to prevent the flow of liquids from dripping or dripping into underground trenches. Caused a combustion explosion and caused damage to neighboring plants.

( 4 ) Class A, B and C liquid warehouses shall be provided with facilities for preventing the dispersion of liquids. For example, a 150 to 300-mm diffuse slope is built at the door of a barreled warehouse or a threshold of 150 to 300 mm is built at the entrance of the warehouse , and sand is filled on both sides of the threshold to form a diffuse slope for easy loading and unloading.

( 5 ) Storehouses in the event of wet combustion and explosion will take measures to prevent water from being impregnated. If the indoor ground is kept above the outdoor ground and the warehouse roof is covered tightly to prevent leakage of rainwater, the stacking platform for loading and unloading such items shall be provided with shelter against rainwater.

3. Pressure relief facility settings

The effectiveness of the installation of pressure relief facilities is mainly checked on explosion-prone plants or warehouses, factories or warehouses where there is a risk of explosion. The inspection requirements are:

( 1 ) Type A and B plants with explosion hazards should adopt open or semi-open type, and the load-bearing structure should adopt reinforced concrete or steel frame and bent structure.

( 2 ) Pressure relief facilities should be made of lightweight roofing panels, lightweight walls, doors and windows that are susceptible to pressure relief, and materials that do not produce sharp debris during explosion, such as safety glass. The quality of lightweight roof panels and walls as pressure relief facilities should not exceed 60 kg /m2 .

( 3 ) Pressure relief facilities should be set up to avoid densely populated areas and major traffic routes, and should be located close to areas where there is a risk of explosion. In silos with dust explosion hazard, pressure relief facilities are located on the top cover. Pressure relief facilities on the roof take anti-icing measures.

( 4 ) A class A factory that emits combustible gas and combustible vapor that is lighter than air should adopt lightweight roofing as pressure relief area. The ceiling is as flat as possible and there is no dead space. The upper space of the factory building is well ventilated.

( 5 ) The area of ​​pressure relief provided by the building with explosion hazard, the working tower of the grain silo and the upper corridor is strictly determined by calculation.

4. Arrangement of change and distribution stations adjacent to explosion hazardous locations

( 3 ) When the transformer station is a positive pressure room and is located in Zone 1, Zone 2 , the indoor ground should be about 0.6m higher than the outdoor ground .

Section II   Electrical explosion

Check content

1. Wire material

The wiring project of explosion hazardous environment, because of the poor mechanical strength of aluminum wire, easy to break, the need for transitional connection and increase the junction box, while the connection technology is difficult to control and ensure the quality, so do not use aluminum, and use copper Insulated wire or cable. Copper wire or cable cross-section in the area of 2.5mm 2 or more 1, zone 2 is 1.5mm 2 or more.

2. Conductor allows the carrying capacity

In order to avoid overload, short-circuit the wires to prevent overheating of an ignition source burned or allowed carrying capacity of insulated wires and cables not less than 1.25 times and 1.25 times the automatic switch melt fuse rated current through the rectifier blurting long delay is a constant current .

Section III Facilities Explosion

1, ventilation and air conditioning system

Ventilation and air-conditioning systems in explosion-hazardous locations have caused fire and explosion accidents due to the absence of effective measures for the discharge of fire and explosion hazardous materials or due to the lack of matching of exhaust fans and motors. During the fire inspection, the ventilation and air conditioning system's pipe laying, ventilation equipment selection, dust collector and filter settings, and grounding device settings are checked to verify whether the ventilation and air conditioning system settings in flammable and explosive locations meet the current national engineering requirements. The requirements for building fire technology standards.

2. Selection of ventilation equipment

For rooms containing flammable and explosive dangerous substances in the air, check whether the delivery and exhaust systems use explosion-proof ventilation equipment. When the blower is arranged in a separate partitioned ventilation room and a backflow prevention device is provided on the ventilation pipe, an ordinary type of ventilation device can be used. For the gas-fired boiler room, check whether explosion-proof accident exhaust fans are selected and the amount of exhaust air is not less than 12 times /h .

3. Setting of dust remover and filter

For exhaust fans that exclude air containing combustion and explosion hazard dust, check whether the dust collector before entering the exhaust fan adopts a dust collector that does not generate sparks; for dust that may form an explosion when exposed to water, the use of a wet dust collector is strictly prohibited.

4. Setting of grounding device

For exhaust ventilation systems that exclude gases or vapors and dusts that are combustible or explosive, and mechanical ventilation in fuel or gas-fired boiler rooms, check whether grounding devices are provided to remove static electricity.

Inspection Method

Through inspection of fire design documents, ventilation and air-conditioning plan and equipment materials, hidden construction records, product quality certification documents and related data for ventilation and air-conditioning equipment, to understand the use of the building, the scale, whether there is a dangerous place or part of the explosion after checking the contents of The project carried out on-site inspections to verify the consistency of product quality certification documents such as fan selection and grounding devices and fire design documents.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.